Safety device for steering motor vehicles



March 28, 1939. i H. L.. BAUMER SAFETY DEVICE FOR STEERING MOTORVEHICLES Filed Feb. 26, 1937 2 Sl1etSSheet l lum@ March 28, 1939. H. l..BAUMER SAFETY DEVICE FOR STEERING MOTOR VEHICLES Filed Feb. 26, 1937 2Sheets-Sheet 2 Patented Mar. 28, 1939` UNITED STATES SAFETY DEVICE FORSTEERING M VEHICIE PATENT `OFFICE V somme.

'I'his invention relates to an improved steering device for motorvehicles, and the primary object of the present invention is to providea fluidpressure operated means for actuating the steering gear of amotor vehicle, so as to decrease the labor of steering and at the sametime increase safety in driving.

The present invention contemplates a power steering device of. the abovekind in which a fluid-pressure motor is associated with the tie rodconnecting the steering knuckles of the motor vehicle, and a furtherobject of the present invention is to provide improved means formounting this Huid-pressure motor on the intermediate or main front axlemember of the vehicle for free movement forwardly or rearwardly with thetie rod and with respect to said main front axle member when the frontsteering wheelsof the vehicle are turned.

A still further object of the present invention is to provide a novelform of valve and operating means therefor, for controlling the ow ofpressure iiuid to and from the uid-pressure motor, whereby steering ofthe vehicle may be conveniently and effectively controlled by operationof the usual steering shaft of the steering column or post of the motorvehicle. y

Other objects and features of the present invention will become apparentfrom the following description when considered in connection with theaccompanying drawings, in which: c

Figure i is a plan view of part of a motor vehicle chassis equipped witha steering device embodying the present invention.

Figure 2 is a fragmentaryelevational view of 'the construction shown inFigure 1, illustrating the control valve and its connection with thesteering shaft.

Figure 3 is an enlarged fragmentary section on line 3 3 of Figure 1. x

Figure 4 is an enlarged section through the uuid-pressure motor on line4 4 of Figure 3.

Figure 5 is a transverse section on line 5 5 of Figure 1; and u Figure 6is an enlarged section on line 6 6 of Figure 2.

Referring in detail to the drawings, the usual front steering andsupporting wheels 5 are journaled on stub axles of steering knuckles 6pivoted at 'I to the ends of a mainor intermediate front axle section 8,the steering knuckles 6 being -connected by the usual tie rod 9. Thevehicle also has the usual steering post or column Ill in which isjournaled a steering shaft I I which may carry the usual steering handleor wheel at its (Cl. 18m-79.2)

upper end and which is operatively` geared atits lower end and within agear box I2 with a deH pending steering arm I3. The arm I3 is usuallyconnected by a drag link with a second steering arm rigidly connectedwith the left hand steering 5 knuckle 6, which parts are omitted whenthe vehicle is equipped with the present steering device.

In accordance with the present invention, a fluid-pressure motor issupported by the main l axle section 8 and includes a cylinder I4through which the tie`rod 9 extends, and a piston I5 carried by said tierod 9 and movable inthe cylinder I4. As the wheels are turned orsteered, .there will be a movement forwardly or rearwardly, of l tie rod9 with respect to axle section 8, and I provide novel means for mountingthe cylinder Il on the axle 8 so as to permit said cylinder to partakeof these movements of tie rod 9. As shown, such means consists of asubstantially C-shaped bracket I6 firmly bolted at I] to theintermediate portion of axle section 8 and includ-` ing rearwardlyprojecting upper and lower arms I 8 and I 9 respectively provided attheir rear ends with shoes 20 and 2I which are in spaced relation 25 andface toward each other. These shoes slidably engage in transverseguideways provided at the top and bottom of the intermediate portion ofcylinder I4, so that the cylinder I4 is slidably mountedbetween theshoes 20 and 2l for rear- 30 ward or forward sliding movement withrespect to axle section 8,' although restrained against movementtransversely of the vehicle. 'Ihe guideways in which shoes 20 and 2Iengage are formed at 23 and 42li oi a flanged collar or ring 35 formedof half sections tightly bolted about the cylinder I 4 as at 25, forconvenience and economy of manufacture and assembly.

A novel form of valve 26, of the turn plug type, is operativelyconnected to steering arm Aturning the steering wheels 5. As shown moreclearly in Figures 2, 5 and 6, this valve includes 45 a suitable casingprovided ateach of opposite sides with a relatively large supply port 2land' a relatively smaller exhaust port 28, as well as having at itsinner end a supply port 29 adapted Y to be connected by a pipe 30 withthe source of 50 fluid under pressure4 which may consist of a storagetank 3l. vThe tank 3| preferably has a safety pressure relief valve 32and may be supplied with air or other iiuid under pressure through acheck controlled inlet pipe 33, .an

engine driven compressor having its outlet connected to pipe 31 in casethe pressure fluid is air. The control valve further includes a turnplug 34 rotatably iltted in the casing of the valve and having anangular passage 35 therethrough at its inner end and an angular passage36 therethrough at its' outer end. The supply ports 21 of the controlvalve are connected by pipes 31 with opposite ends of cylinder I4,respectively, as shown clearly in Figures 1 and 4. In a like manner, theexhaust ports 28 of the valve are connected by smaller pipes 38 withopposite ends of cylinder I4, respectively. The arrangement is such thatwhen plug 34 is in the 'position of Figure 6, communication isestablished between supply pipe 30 and the pipe 31 which connects withthe left hand `end of cylinder I4, communication being simultaneouslyestablished between passage 36 and the exhaust pipe 3l which connectswith the right hand end of cylinder I4. Thus, as fluid under pressure isallowed to flow into the left hand end of cylinder I 4 for moving thepiston I5 to the right and thereby steering the vehicle to the left, thepressure fluid in the right hand end of cylinder I4 is allowed to escapetherefrom, ultimately exhausting into the atmosphere through passage 36of the control valve, one end of said passage 36 being open to theatmosphere as shown at 3S. Due to the fact that the pipes 33 and ports23 are relatively small, a back pressure will be maintained on theexhausting pressure fluid so as to insure steady movement of piston I5as required for smooth and safe steering. The reverse of this operationtakes place when the plug 34 is turned one-half revolution so as toprovide communication between supply pipe 30 and the other pipe 31 andto simultaneously establish communication between the other pipe 38 andthe atmosphere by way of passage 36, the piston Il then `being moved tothe left for turning the steering wheels i so as to steer the vehicle tothe right. Obviously, a quarter turn of plug 34 intermediate these twopositions will result in cutting o all communication between supply pipe30 and pipes 31 andv 3l so that the piston I5 will be maintained in adesired position. Naturally, as soon as the desired turning movement ofthe vehicle has been accomplished, the power is utilized to return thesteering wheels to their normal position for travel straight ahead,whereupon the valve is turned to ci! position so as to maintain thisnormal condition of steerins wheeis I.

A. compression spring s seats the turn plug 34 in the tapered bore ofthe valve casing, and a cap c is threaded on one end of said valvecasing to adjust the tension of said spring. Besides compensating forwear, this permits the turn plug 34 to lift against the action of springs to act as a safety valve and relieve excess pressure when necessary.

The valve 23 is mounted on a side rail 4I of the chassis frame of thevehicle by means of an angular bracket 4I as clearly shown in Figures 2and i5.v 'I'his bracket has an upper horizontal portion receiving thelower ilange of chassis rail 43 and secured thereto by set screws 42,the other or depending portion of bracket 4I having a threaded openinginto which is screwed the inner end of valve 26 so as to support thelatter transversely of the vehicle in front of the steering arm I3. Theportion of plug 34 provided with passage 36 projectsfoutwardly from thevalve casing and forms a stem on which is secured an operating arm 43operatively connected with the steering arm I3 by a link-44,` Thus, theoperation of valve 24 is established by the usual manual turning ofsteering shaft Il of steering column Il. The opening in bracket 4I intowhich valve 2l :is threaded is indicated at 45. Also, it is obvious thatthe pipes 31 and 33 may have any suitable provision for permittingflexing thereof where required so as to not interfere with the movementof tie rod 9 and cylinder I4 forwardly or r'earwardly with respect tomain axle section 8.

From the foregoing description, it is believed that the constructionandv operation, as well as the advantages of the present invention, willbe readily understood and appreciated by those skilled in the art. Thedevice is'simple and compact in construction, easy to install,convenientv to control, and efficient in operation. There are a minimumnumber of vmovable parts likely to get 'out of order and these are of adurable and long lasting nature. While the present device has beenillustrated as the sole steering means, it may obviously be used jointlywith the `usual manual operation by simply retaining the mechanicalconnection between steering arm I3 and the arm 6a of the left handsteering knuckle 6. Manually operable relief valves 46 may be providedon the ends of cylinder I4 and opened to permit free movement of pistonI5, whenever it may be desired to manually steer the vehicle in theusual way.

It will be seeny that, in the event of a blowout of a tire of one of the.wheels 5 or should said wheels strike an object or rut on the road, noshock will be transmitted to the steering shaft II, and under allconditions the wheels 5 will be maintained as set by the fluid-pressuremotor so as lto insure eilortless, safe steering at all main axlesection so as to restrain saidcylinder against movement transverselyV ofthe vehicle and permit free movement of the cylinder forwardly orrearwardly relative to said main front axle section, said last-namedmeans comprising azvertical substantially C-shaped bracket rigidlysecured intermediate its ends to said main axle section and includingrearwardly extending spaced upper and lower arms provided with endshoes. said cylinder having top and bottom transverse guidewaysintermediate the ends thereof in which said shoes are slidably engaged.

2. In a compressed-air operated steering device for a motor vehicle,wherein a compressedair motor is operatively associated with thesteering knuckle tie rod of the vehicle, means for controlling theoperation of said compressed-air motor including a control valve of theturn plug type, a bracket `carried bya side chassis rail of the vehicleand having a threaded opening, one end of said control valvebeingthreaded into said opening of the bracket so as to support said valvetransversely of the vehicle` forwardly of the steering arm geared to thesteering shaft of said vehicle, an arm carried by the rotatable Cil ,plug of said control valve, and a link operatively control valve of theturnplug type including a casing provided at each of opposite sides witha supply port and a relatively smaller exhaust port, a turn plugjournaled in said casing and provided at each end with an angularpassage, said angular passages respectively opening through oppositeends of the turn plug for respective connection with a source of airunder pressure and for communication with the atmosphere, one of saidangular passages being arranged to connect the source of air underpressure with either desired supply port depending upon the position towhich said turn plug is turned, and the other, angular passage beingadapted to simultaneously connect a predetermined exhaust port with theatmosphere, said angular passages being further so formed and arrangedthat turning of said turn plug will regulate the flow of' air underpressure to either end of the motor and simultaneously correspondinglyregulate the exhaust of air from the other end of said motor.

4. In combination with the running gear of an automobile includingsteering knuckles connected by a tie rod, a compressed-air motoroperatively connected to said tie rod and including a cylinder having apiston movable therein,

' a source of air under pressure, a control valve operable toselectively provide communication between either desired end of saidcylinder and the source of air under pressure and to simultaneously openan exhaust line from the other end of the cylinder to the atmospherewith the ow of the compressed air to one end of the cylinder regulatedand the ow of the exhaust to the atmosphere restricted andcorrespondingly regulated so as to maintain a constant controlledbackpressure on the opposite side of said piston from that against whichthe air under pressure is admitted.

5. In a compressed air operated vehicle steer-y ing device having acompressed-air motor, a control valve of the turn plug type including acasing having a tapered bore and provided at each of opposite sides witha supply port and a relatively smaller exhaust port, a tapered turn plugjournaled in said casing and provided at each end with an angularpassage, a compression spring seating said turn plug in said bore, meansto adjust the compression of said sprinf, said angular passagesrespectively opening through the opposite smaller and larger ends of theturn plug for respective connection with a source oil air under pressureand for communication with the atmosphere, one of said angularpassagesbeing arranged to connect the source of air under pressure witheither desired supply port depending'upon the position to whichv saidturn-plug is turned, and the other angular passage being adapted tosimultaneously connect a predetermined exhaust port with the atmosphere,said angular passages being further soformed and arranged that turningof said turn plug will regulate the ow of air under pressure to either-end of the motor and simultaneously correspondingly regulate theexhaust of air from the other end of said motor.

HARRY LELAND BAUMER.

